1. Field of the Invention
The present invention relates to a laying head with laying pipe for a rapidly movable wire rod and including a support housing, a carrying sleeve located in the support housing for receiving a wire entrance section of a laying pipe, two, spaced from each other bearings secured in the support housing for supporting the carrying sleeve; a pipe holder projecting past an end surface of the carrying sleeve remote from a carrying sleeve section that receives the wire entrance section of the laying pipe, for supporting a wire laying section of the laying pipe.
2. Description of the Prior Art
With the laying heads of a type described above, a wire rod, which is fed from a wire rolling train and moves with a high speed, enters a wire entrance section of the laying pipe, which is located in the axial region of the carrying sleeve, and is guided toward the laying section of the laying pipe which is radially spaced from the central axis of the carrying sleeve and is formed as a circular section. The wire rod, upon exiting the mouth of the circular section, falls in form of coils on a further conveyor. The above described laying head is disclosed in European Publication EP-A2 965 396 and EP-A1 679 453.
Because the wire rod is fed from modem wire rolling trains with a high speed, the laying head should likewise be driven with a high speed. Therefore, the laying pipe, which transforms the linearly movable wire rod in circular windings or coils, should be held by the pipe holder in as stable position as possible. It is to be noted in particular that the specific guide profile of the laying head leads to concentration of circulating masses at the most remote from the carrying sleeve, overhanging section of the pipe holder.
With this design which, as a rule, includes a radial bearing as a movable bearing and a stationary bearing, the overhanging of the pipe holder causes a essentially permanent deflection of the carrying sleeve in the space between the two bearings, which is associated with a run-out resulting from the circulation of the wire rod. Both these phenomena lead during the operation of the laying head, as a result of a high and constantly increasing rolling speed of the wire rolling train, to critical whirling speeds which, if exceeding a certain value, can cause dangerous pendulum swingings of the pipe holder and the laying pipe, which also can cause frequent circular movements of the bearings and the bearing fatigue.
Accordingly, an object of the present invention is to eliminate the drawbacks of the conventional laying head and, in particular, the phenomena associated with the pendulum swinging of the pipe holder and the laying pipe.
This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing in the laying head housing a pressing device for applying a radial pressure to the section of the carrying sleeve located between the two bearings.
According to one embodiment of the present invention, the pressing device includes a bearer with a plurality of pressing rollers that engage the cylindrical section of the carrying sleeve, applying pressure thereto. The bearer is displaced in a radial direction, transverse to the axis of the carrying sleeve, by spring, electrical, or hydromechanical means.
According to a further embodiment of the present invention, the pressing device includes a pressure bush which surrounds the cylindrical section of the carrying sleeve, applying pressure thereto. The bush applies to the sleeve section an adjustable, vertically directed hydrostatic and/or hydromechanical pressure. The pressure bush can be formed with a per se known conically extending inner surface so that the bush can be axially displaced over the sleeve section to properly position, in the axial direction, the application point of the pressure.
According to a still further embodiment of the present invention, the pressing device includes a magnetic bearing that surrounds the cylindrical section of the carrying sleeve. The direction and the amount of the magnetic forces the magnets of the magnet bearing apply to the sleeve section are adjustable.
The pressing device can also be formed of an axially adjustably displaceable slide bearing that applies a radial pressure to the sleeve section.
Providing of the pressing device permits to eliminate an undesirable additional loading of the carrying sleeve supporting bearings, in particular of the bearing that adjoins the pipe holder. In additional, the pressuring device permits to substantially reduce the swinging level of the pipe holder and the laying pipe and insures a disturbance-free operation even if the rolling speed of the wire rolling would increase still further.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to is construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.